In the midst of the intense congressional hearings on Syria, many longtime observers had questions that had nothing to do with a possible military strike: Why did Secretary of State John Kerry look so different? His eyes seemed less droopy than usual, his entire face seemed somehow wider.

Simple explanation, said his personal spokesman Glen Johnson. Kerry has been working non-stop with no vacation — and barely has had time to squeeze in a simple haircut.

But that didn’t stop the speculation.

“It’s looks to me that he has limited movement on the left side of his face,” said cosmetic dermatologist Tina Alster.

“He doesn’t have any movement in his face at all,” said plastic surgeon Barry Cohen.

It could also be one of many other possibilities. Lack of sleep — no surprise, given the last couple of months with his wife’s illness and the Syrian crisis. Or something as simple as allergies, which could cause his eyes and face to puff up. It could be a minor cosmetic procedure like Botox or another injectable, or Bell’s palsy, a common virus which affects facial nerves and can mimic a minor stroke or bad Botox. Or simply stress.

“Stress can always make you look not like yourself,” said Alster. “It can definitely change how your face looks.”

Kerry, 69, is no stranger to speculation about his classic patrician face. In the 1970’s, he had an operation to correct a “malocclusion” — a problem with his bite that caused clicking in his jaw (and yes, made him more handsome). His smooth, unwrinkled  appearance during the 2004 presidential race caused enough of a stir that his campaign was forced to deny Botox rumors directly. And in January of 2012, Kerry showed up at the White House celebration for the Boston Bruins sporting two black eyes. Plastic surgery? Nah, he said — just the result of a nasty spill while playing hockey with family and friends over the New Year’s break.

But the fact that the chatter arose again this week about whether his appearance was the result of exhaustion or some cosmetic snafu annoyed those close to him.

“Not only is it a little sad that this constitutes news by anyone’s definition in Washington when we’re debating the use of force in Syria, but the answer is simple: No, end of story. That’s not a denial, that’s a fact,” Johnson said.

Fueling the rumors is the reality that many of today’s aging politicians (women and men) have artificially tweaked their looks. That makes it almost impossible to distinguish between good genes, natural aging, stress and bad cosmetic work.

Said Cohen: “People are certainly not wearing their wrinkles and age spots with the grace they once did.”